October 07, 2012, 7:28 AM — Starting Tuesday Microsoft platforms will block the use of encryption keys less than 1024 bits so businesses that are still using weaker keys better get busy.
Changing the keys the Microsoft software uses isn't that tricky, but finding all the customer and third-party software in corporate networks that use smaller keys could require some searching.
Also, automated tools such as those sold by ExtraHop and Venafi can help track down applications that won't comply with the Microsoft update.
The change in key length requirements came in the wake of an exploit against Windows Update becoming a key component of Flame malware attacks. Keys less than 1024 bits are deemed too easy to break with brute force attacks.
The patch has been available since August as an option to give customers time to check it out and install it, but after Tuesday it is no longer optional. "There are still a few days left if you haven't tested it, but don't let this be an 'I told you so' moment," says Paul Henry, security and forensic analyst at Lumension.
The upgrade does have some wiggle room. Applications signed before Jan. 1, 2010, are allowed to use keys smaller than 1024 bits.
The deadline coincides with October's Patch Tuesday, which for the second month in a row is pretty light, featuring just one critical bulletin.
It apparently addresses a long-standing flaw in code that was repeatedly used in SQL Server from 2000 on. Unpatched, it can allow a remote-code execution on affected platforms.